People are unhappy that Google indexes their shortlinks (#2202 and others). Then people are unhappy that Google does not index their shortlinks (#2970 and others).

Put the google indexing logic into its own function and make it filterable so everybody can use the plugin they want

https://github.com/YOURLS/YOURLS/blob/master/includes/functions.php#L284-L287